Azaoxa heterocyclic compound and method of preparing the same

ABSTRACT

Disclosed is an azaoxa heterocyclic compound represented by the following formula (I):  
                 
 
     (wherein, each symbol is defined the same as in the specification) and a method for preparing the same. This compound of the present invention is prepared by the reaction of a phenolic compound, an aromatic diamine compound and an aldehyde compound. The azaoxa heterocyclic compound of the present invention can be used as a hardening resin or a hardener for an epoxy resin, polyether and a resin containing active hydrogen atoms, wherein the composition formed by the azaoxa heterocyclic compound and the epoxy resin is useful in the application of laminates, adhesive, semiconductor packaging materials and phenolic resin forming materials.

FIELD OF THE INVENTION

[0001] The present invention relates to an azaoxa heterocyclic compoundused as a hardening resin or a hardener for an epoxy resin, polyetherand a resin containing active hydrogen atoms and a method for preparingthe azaoxa heterocyclic compound.

BACKGROUND OF THE INVENTION

[0002] Thermosetting resins, such as phenolic resins, melamine resins,epoxy resins, unsaturated polyester resins, bismaleimide resins and thelike, are widely applied in a variety of industry fields. However, theseresins still suffer from many disadvantages, for example, the generationof volatile by-products on curing of phenolic resins or melamine resins,the poor inflammability of epoxy resins and unsaturated polyester resinsand the extremely high price of bismaleimide resins. To solve the aboveproblems, there have been made attempts to develop the thermosettingresins having the benzoxazine cyclic structure.

[0003] The resin having the benzoxazine cyclic structure has becomeanother choice of the thermosetting resins since the thermal stabilityof such a resin is similar to that of phenolic resins, epoxy resins andother thermosetting resins. The thermosetting resins having thebenzoxazine cyclic structure are cured by the ring-openingpolymerization of the benzoxazine rings. Generally, the compounds havingthe benzoxazine cyclic structure is prepared by the reaction of aphenolic compound, an amine compound and an aldehyde compound. But manypatents disclose the method for preparing the compounds having thebenzoxazine cyclic structure, which are prepared by the reaction ofaniline and phenolic compound. U.S. Pat. No. 6,005,064 disclosed thethermosetting resin having the benzoxazine cyclic structure prepared bythe reaction of a phenolic resin, formaldehyde and aniline; andJP-A-Hei-11-50123 also disclosed the method for preparingdihydrobenzoxazine thermosetting resin from bisphenol, aniline andformalin and using methyl ethyl acetone as a solvent. However, anilineused in these preparing method is toxic, and is a forbidden chemicalmaterial by the law. The preparation method cannot meet the requirementswith the mass production in industry.

[0004] JP-A-Hei-11-50123 discloses a method for preparingdihydro-benzoxazine thermosetting resin by using methanol as a solventand undergoing the reaction of phenol, 4,4′-diaminodiphenylmethane andparaformaldehyde. This patent only mentioned that phenol is used as areactant, but not mentioned that a relatively pure azaoxa heterocycliccompound can be prepared by reacting phenolic compound havingsubstituent such as alkyl, alkoxy, alkenyl groups and the like witharomatic diamine. Furthermore, methanol used in the preparing method hashigh polarity and has relatively large dielectric constant. Whenmethanol is miscible with reactants in an autoclave, the gelation easilyoccurs and an agglomeration is formed, which results in the instabilityof the reaction system. On the other hand, if the temperature-control isimproper in the reaction system, the compound having the benzoxazinecyclic structure formed by the condensation will further undergopolymerization due to the ring opening at the high temperature., thusresulting in low productivity and a failed reaction.

[0005] As described above, many published references disclosed themethod for preparing the compound having the benzoxazine cyclicstructure. However, these references all did not mention that aparticular solvent is used to improve the stability of the reactionsystem. Therefore, the present inventors have conducted extensivestudies in order to overcome the above mentioned problems. As a result,they have found that the system was endowed with relatively highstability as using the hydrocarbon solvent to conduct the reaction ofphenolic compounds, aromatic diamines and aldehyde compounds. Inaddition to preventing the ring-reopening polymerization at hightemperature due to improper temperature control, the present inventionprevents the gelation or agglomeration caused by using high polarsolvent or protic solvent to undergo the reaction. The azaoxaheterocyclic compound having the benzoxazine cyclic structure obtainedis pure and has low water absorbency if the reaction is conducted byusing a substituted phenolic compound (particularly alkyl phenoliccompound) and an aromatic diamine compound as reactants instead of usinghigh toxic aniline. The azaoxa heterocyclic compound is particularlyuseful in preparing laminates (CCL), copper foil adhesives,semiconductor packaging materials and phenolic resin forming materials.

SUMMARY OF THE INVENTION

[0006] The present invention provides an azaoxa heterocyclic compoundrepresented by the following formula (I):

[0007] wherein, R₁, R₂, R₃, m and n is defined as the following detaileddescription section.

[0008] It is another object of the present invention to provide a methodfor preparing azaoxa heterocyclic compounds having the benzoxazinecyclic structure. The method is characterized by using a phenoliccompound, an amine compound and an aldehyde compound as reactants in ahydrocarbon solvent to coundergo the reaction.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is an IR spectrum of the azaoxa heterocyclic compoundobtained in Example 1 according to the present invention.

[0010]FIG. 2 is a GPC spectrum of the azaoxa heterocyclic compoundobtained in Example 1 according to the present invention.

[0011]FIG. 3 is an IR spectrum of the azaoxa heterocyclic compoundobtained in Example 2 according to the present invention.

[0012]FIG. 4 is a GPC spectrum of the azaoxa heterocyclic compoundobtained in Example 2 according to the present invention.

[0013]FIG. 5 is an IR spectrum of the azaoxa heterocyclic compoundobtained in Example 3 according to the present invention.

[0014]FIG. 6 is a GPC spectrum of the azaoxa heterocyclic compoundobtained in Example 3 according to the present invention.

[0015]FIG. 7 is an IR spectrum of the azaoxa heterocyclic compoundobtained in Example 4 according to the present invention.

[0016]FIG. 8 is a GPC spectrum of the azaoxa heterocyclic compoundobtained in Example 4 according to the present invention.

[0017]FIG. 9 is an IR spectrum of the azaoxa heterocyclic compoundobtained in Example 5 according to the present invention.

[0018]FIG. 10 is a GPC spectrum of the azaoxa heterocyclic compoundobtained in Example 5 according to the present invention.

[0019]FIG. 11 is an IR spectrum of the azaoxa heterocyclic compoundobtained in Comparative Example 1 according to the present invention.

[0020]FIG. 12 is a GPC spectrum of the azaoxa heterocyclic compoundobtained in Comparative Example 1 according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention provides an azaoxa heterocyclic compoundrepresented by the following formula (I):

[0022] wherein, R₁ represents one selected from the group consisting ofan alkyl group, an alkenyl group, an alkoxyl group, a hydroxy group,halogen and an amino group, R₂ represents one selected from the groupconsisting of a bond, an alkylene group, O, S and SO₂, and R₃ representsH or C₁₋₆ alkyl group; m is an integer of 0 to 4; and n is an integer of1 to 4.

[0023] In the azaoxa heterocyclic compounds represented by the aboveformula (I), the alkyl group represented by R₁ and R₂ means linear,branched or cyclic alkyl of 1 to 6 carbon atoms, examples thereofinclude methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl,amyl, hexyl, 2-ethylhexyl, cyclohexyl and the like. Alkoxy group meanslinear, branched or cyclic alkoxyl of 1 to 6 carbon atoms, examplesthereof include methoxy, ethoxy, propoxy, isopropoxy, butoxy, s-butoxy,t-butoxy, amoxy, hexoxy, cyclohexoxy and the like. Alkylene group meanslinear, branched or cyclic alkylene group of 1 to 6 carbon atoms,examples thereof include methylene, ethylene, propylene, butylene,2-methylpropylene, amylene, 2,2′-dimethyl propylene, hexylene,2,3-dimethylbutylene and the like.

[0024] The azaoxa heterocyclic compounds of the present invention areprepared by the reaction of a phenolic compound, an amine compound andan aldehyde compound in a hydrocarbon solvent.

[0025] The phenolic compounds used for preparing the azaoxa heterocycliccompound of the present invention is represented by the followingformula (II):

[0026] wherein R₁ and n are as defined above.

[0027] The preferred phenolic compounds used for preparing the azaoxaheterocyclic compound of the present invention are alkylphenoliccompounds. The azaoxa heterocyclic compound having the benzoxazinecyclic structure obtained by using an alkylphenolic compound as areactant is purer and has low water absorbency, which is particularlyuseful in preparing a variety of materials used in electronicapplication.

[0028] Examples of the above-mentioned alkylphenol include, but are notlimited to, cresol, ethylphenol, propylphenol, butylphenol,s-butylphenol, t-butylphenol, amylphenol, isoamylphenol, hexylphenol,cyclohexylphenol, allylphenol, 2-hydroxy-4-cresol, 3-hydroxy-4-cresol,2-hydroxy-4-ethylphenol, 3-hydroxy-4-ethylphenol,2-hydroxy-4-propylphenol, 3-hydroxy-4-propylphenol,3-hydroxy-4-propylphenol, 3-fluoro-4-cresol, 2-bromo-4-cresol,3-bromo-4-cresol, 2-fluoro-4-ethylphenol, 3-fluoro-4-ethylpheno,2-chloro-4-ethylphenol, 3-chloro-4-ethylphenol, 2-bromo-4-ethylphenol,3-bromo-4-ethylphenol, 2-amino-4-cresol, 3-amino-4-cresol,2-amino-4-ethlphenol, 2-amino-4-cresol, 3-amino-4-cresol,2-amino-4-ethylphenol, 3-amino-4-ethylphenol, 2-amino-4-propylphenol,3-amino-4-propylphenol and the like.

[0029] Examples of the alkylphenolic compounds which may be substitutedwith a hydroxymethyl group include 4-hydroxymethyl-2-cresol,4-hydroxymethyl-3-cresol, 4-hydroxymethyl-2-ethylphenol,4-hydroxymethyl-3-ethylphenol, 4-hydroxymethyl-2-n-propylphenol,4-hydroxymethyl-3-n-propylphenol, 4-hydroxymethyl-2-isopropylphenol,4-hydroxymethyl-3-isopropylphenol, 4-hydroxymethyl-2-n-butylphenol,4-hydroxymethyl-3-n-butylphenol, 4-hydroxymethyl-2-s-butylphenol,4-hydroxymethyl-3-s-butylphenol, 4-hydroxymethyl-2-t-butylphenol,4-hydroxymethyl-3-t-butylphenol, 4-hydroxymethyl-2,3-dimethylphenol,4-hydroxymethyl-2,5-dimethylphenol, 4-hydroxymethyl-3,5-dimethylphenol,4-hydroxymethyl-2,3,5-trimethylphenol and the like.

[0030] Examples of the alkylphenolic compounds which may be substitutedwith an isopropyl group include 4-isopropyl-2-cresol,4-isopropyl-3-cresol, 4-isopropyl-2-ethylphenol,4-isopropyl-3-ethylphenol, 4-isopropyl-2-n-propylphenol,4-isopropyl-3-n-propylphenol, 2,4-diisopropylphenol,3,4-diisopropylphenol, 4-isopropyl-2-n-butylphenol,4-isopropyl-3-n-butylphenol, 4-isopropyl-2-s-butylphenol,4-isopropyl-3-s-butylphenol, 4-isopropyl-2-t-butylphenol,4-isopropyl-3-t-butylphenol, 4-isopropyl-2,3-dimethylphenol,4-isopropyl-2,5-dimethylphenol, 4-isopropyl-3,5-dimethylphenol,4-isopropyl-2,3,5-trimethylphenol and the like.

[0031] Examples of the alkylphenolic compounds which may be substitutedwith a vinyl group include 4-vinyl-2-cresol, 4-vinyl-3-cresol,4-vinyl-2-ethylphenol, 4-vinyl-3-ethylphenol, 4-vinyl-2-n-propylphenol,4-vinyl-3-n-propylphenol, 4-hydroxymethyl-2-isopropylphenol,4-vinyl-3-isopropylphenol, 4-vinyl-2-n-butylphenol,4-vinyl-3-n-butylphenol, 4-vinyl-2-s-butylphenol,4-vinyl-3-s-butylphenol, 4-vinyl-2-t-butylphenol,4-vinyl-3-t-butylphenol, 4-vinyl-2,3-dimethylphenol,4-vinyl-2,5-dimethylphenol, 4-vinyl-3,5-dimethylphenol,4-vinyl-2,3,5-trimethylphenol and the like.

[0032] Examples of the alkylphenolic compounds which may be substitutedwith an amino group include 4-amino-2-cresol, 4-amino-3-cresol,4-amino-2-ethylphenol, 4-amino-3-ethylphenol, 4-amino-2-n-propylphenol,4-amino-3-n-propylphenol, 4-amino-2-isopropylphenol,4-amino-3-isopropylphenol, 4-amino-2-n-butylphenol,4-amino-3-n-butylphenol, 4-amino-2-s-butylphenol,4-amino-3-s-butylphenol, 4-amino-2-t-butylphenol,4-amino-3-t-butylphenol, 4-amino-2,3-dimethylphenol,4-amino-2,5-dimethylphenol, 4-amino-3,5-dimethylphenol,4-amino-2,3,5-trimethylphenol and the like.

[0033] Examples of other phenolic compounds used for preparing theazaoxa heterocyclic compound of the present invention include, but arenot limited to, 4-methoxyphenol, 3-methoxyphenol, 2-methoxyphenol,4-vinylphenol, 3-vinylphenol, 2-vinylphenol, 4-hydroxyphenol,3-hydroxyphenol, 2-hydroxyphenol, 4-aminophenol, 3-aminophenol,2-aminophenol, 4-hydroxymethylphenol, 3-hydroxymethylphenol,2-hydroxymethylphenol, 4-hydroxymethyl-2-hydroxyphenol,4-hydroxymethyl-3-hydroxyphenol, 4-hydroxymethyl-2,5-difluorophenol,4-hydroxymethyl-2,5-dichlorophenol, 4-hydroxymethyl-2,5-dibromophenol,4-isopropyl-2-methoxyphenol, 4-isopropyl-m3-methoxyphenol,4-isopropyl-2-hydroxyphenol, 4-isopropyl-3-hydroxyphenol,4-isopropyl-2,5-difluorophenol, 4-isopropyl-2,5-dichlorophenol,4-isopropyl-2,5-dibromophenol, 4-vinyl-2-methoxyphenol,4-vinyl-3-methoxyphenol, 4-vinyl-2-hydroxyphenol,4-vinyl-3-hydroxyphenol, 4-vinyl-2,5-difluorophenol,4-vinyl-2,5-dichlorophenol, 4-vinyl-2,5-dibromophenol and the like.

[0034] The phenolic compounds used for preparing the azaoxa heterocycliccompound of the present invention are not particularly limited. Thephenolic compounds can be mono-functional phenolic compounds,bi-functional phenolic compounds and multi-functional phenoliccompounds, provided that at least one of hydrogen atoms onortho-positions to the hydroxy group in the aromatic ring isunsubstituted.

[0035] The aromatic diamine compounds used for preparing the azaoxaheterocyclic compound of the present invention is represented by thefollowing formula (III):

[0036] wherein R₃ and m are as defined above.

[0037] The aromatic diamine compounds represented by the formula (III)include, but are not limited to, diaminobiphenyl compound,diaminodiphenylalkane compound, diaminodiphenyl ether compound,diaminodiphenyl thioether compound and diaminodiphenyl sulfone compound.

[0038] Examples of the diaminobiphenyl compound include, for example,4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-dimethylbiphenyl,4,4′-diamino-2,2′-diethylbiphenyl, 4,4′-diamino-2,2′-isopropylbiphenyl,4,4′-diamino-2,2′-dibutylbiphenyl, 4,4′-diamino-2,2′-di-s-butylbiphenyl,4,4′-diamino-3,3′-dimethylbiphenyl, 4,4′-diamino-3,3′-diethylbiphenyl,4,4′-diamino-3,3′-dipropylbiphenyl,4,4′-diamino-3,3′-diisopropylbiphenyl,4,4′-diamino-3,3′-dibutylbiphenyl, 4,4′-diamino-3,3′-di-s-butylbiphenyl,4,4′-diamino-2-butyl-3-methylbiphenyl,4,4′-diamino-2-butyl-3-ethylbiphenyl,4,4′-diamino-2-butyl-3-propylbiphenyl,4,4′-diamino-2′-butyl-3-isopropylbiphenyl,4,4′-diamino-2-ethyl-3-methylbiphenyl,4,4′-diamino-2-ethyl-3-propylbiphenyl,4,4′-diamino-2-ethyl-3-isopropylbiphenyl,4,4′-diamino-2-methyl-3-propylbiphenyl, 4,4′-diamino-2-methylbiphenyl,4,4′-diamino-3-isopropylbiphenyl.

[0039] Examples of the diaminodiphenylalkane compound include, forexample, dianilinomethane, dianilinoethane, dianilinoisopropane,dianilinopropane, 4,4′-methylene bis(2-methylaniline), 4,4′-methylenebis(2-ethylaniline), 4,4′-methylene bis(2-propylaniline), 4,4′-methylenebis(2-isopropylaniline), 4,4′-methylene bis(2-butylaniline),4,4′-methylene bis(2-s-butylaniline), 4,4′-methylenebis(2-t-butylaniline), 4,4′-methylene bis(2-amylaniline), 4,4′-methylenebis(2-isoamylaniline), 4,4′-methylene bis(2-hexylaniline), 4,4′-ethylenebis(3-methylaniline), 4,4′-ethylene bis(3-ethylaniline), 4,4′-ethylenebis(3-propylaniline), 4,4′-ethylene bis(3-butylaniline), 4,4′-ethylenebis(3-s-butylaniline), 4,4′-ethylene bis(3-t-butylaniline),4,4′-ethylene bis(3-amylaniline), 4,4′-ethylene bis(3-isoamylaniline),4,4′-ethylene bis(3-hexylaniline), 4,4′-methylenebis(2,6-dimethylaniline), 4,4′-methylene bis(2,6-diethylaniline),4,4′-methylene bis(2,6-dipropylaniline), 4,4′-methylenebis(2,6-diisopropylaniline), 4,4′-methylene bis(2,6-dibutylaniline),4,4′-methylene bis(2,6-di-s-butylaniline), 4,4-methylenebis(2,6-di-t-butylaniline), 4,4′-methylene bis(2,6-diamylaniline),4,4′-methylene bis(2,6-diisoamylaniline), 4,4′-methylenebis(2,6-dihexylaniline), 4,4′-ethylene bis(2,5-dimethylaniline),4,4′-ethylene bis(2,5-diethylaniline), 4,4′-ethylenebis(2,5-dipropylaniline), 4,4′-ethylene bis(2,5-diisopropylaniline),4,4′-ethylene bis(2,5-dibutylaniline), 4,4′-ethylenebis(2,5-di-s-butylaniline), 4,4′-ethylene bis(2,5-di-t-butylaniline),4,4′-ethylene bis(2,5-diamylaniline), 4,4′-ethylenebis(2,5-diisoamylaniline), 4,4′-ethylene bis(2,5-dihexylaniline),4,4′-methylene bis(2-butyl-6-methylaniline), 4,4′-methylenebis(2-butyl-6-ethylaniline), 4,4′-methylenebis(2-butyl-6-propylaniline), 4,4′-methylenebis(2-butyl-6-isopropylaniline), 4,4′-methylenebis(2-ethyl-6-methylaniline), 4,4′-methylenebis(2-ethyl-6-propylaniline), 4,4′-methylenebis(2-ethyl-6-isopropylaniline), 4,4′-methylenebis(2-isopropyl-6-methylaniline) and the like.

[0040] Examples of the diaminodiphenyl ether compound include, forexample, 4,4′-diaminodiphenylether, di(4-amino-3-methylphenyl)ether,di(4-amino-3-ethylphenyl)ether, di(4-amino-3-propylphenyl)ether,di(4-amino-3-isopropylphenyl)ether, di(4-amino-3-butylphenyl)ether,di(4-amino-3-s-butylphenyl)ether, di(4-amino-3-t-butylphenyl)ether,di(4-amino-3-amylphenyl)ether, di(4-amino-3-hexylphenyl)ether,di(4-amino-3,5-dimethylphenyl)ether, di(4-amino-3,5-diethylphenyl)ether,di(4-amino-3,5-dipropylphenyl)ether,di(4-amino-3,5-diisopropylphenyl)ether,di(4-amino-3,5-dibutylphenyl)ether, di(4-amino-3,5-diamylphenyl)ether,di(4-amino-3,5-dihexylphenyl)ether and the like.

[0041] Examples of the diaminodiphenyl thioether compound include, forexample, 4,4′-diaminodiphenyl thioether,di(4-amino-3-methylphenyl)thioether, di(4-amino-3-ethylphenyl)thioether,di(4-amino-3-propylphenyl)thioether,di(4-amino-3-isopropylphenyl)thioether,di(4-amino-3-butylphenyl)thioether,di(4-amino-3-s-butylphenyl)thioether,di(4-amino-3-t-butylphenyl)thioether, di(4-amino-3-amylphenyl)thioether,di(4-amino-3-hexylphenyl)thioether,di(4-amino-3,5-dimethylphenyl)thioether,di(4-amino-3,5-diethylphenyl)thioether,di(4-amino-3,5-dipropylphenyl)thioether,di(4-amino-3,5-diisopropylphenyl)thioether,di(4-amino-3,5-dibutylphenyl)thioether,di(4-amino-3,5-diamylphenyl)thioether,di(4-amino-3,5-dihexylphenyl)thioether and the like.

[0042] Examples of the diaminodiphenyl sulfone compound include, forexample, 4,4′-diaminodiphenyl sulfone,di(4-amino-3-methylphenyl)sulfone, di(4-amino-3-ethylphenyl)sulfone,di(4-amino-3-propylphenyl)sulfone, di(4-amino-3-isopropylphenyl)sulfone,di(4-amino-3-butylphenyl)sulfone, di(4-amino-3-s-butylphenyl)sulfone,di(4-amino-3-t-butylphenyl)sulfone, di(4-amino-3-amylphenyl)sulfone,di(4-amino-3-hexylphenyl)sulfone, di(4-amino-3,5-dimethylphenyl)sulfone,di(4-amino-3,5-diethylphenyl)sulfone,di(4-amino-3,5-dipropylphenyl)sulfone,di(4-amino-3,5-diisopropylphenyl)sulfone,di(4-amino-3,5-dibutylphenyl)sulfone,di(4-amino-3,5-diamylphenyl)sulfone,di(4-amino-3,5-dihexylphenyl)sulfone and the like.

[0043] The aldehyde compounds used for preparing the azaoxa heterocycliccompounds of the present invention are not particularly limited,provided that the aldehyde compounds are used for preparing the azaoxaheterocyclic compound having the benzoxazine cyclic structure. Examplesof the aldehyde compound include, but are not limited to, aldehyde (orvapor thereof), paraformaldehyde, polyoxymethylene and the like.

[0044] The azaoxa heterocyclic compounds of the present invention areprepared by the polymerization of a phenolic compound, an aromaticdiamine compound, and a aldehyde compound, wherein the phenoliccompound, the aromatic diamine compound and the aldehyde compound usedin the polymerization are present in a mole ratio of 2:1:4. Incomparison to the conventional azaoxa heterocyclic compound having thebenzoxazine cyclic structure obtained by using an unalkylated phenoliccompound as a reactant, the azaoxa heterocyclic compound of the presentinvention obtained by using an alkylated phenolic compound as a reactantin polymerization is relatively pure and has relatively low waterabsorbency. Meanwhile, in the present invention, the azaoxa heterocycliccompounds having the benzoxazine cyclic structure, which may serve as ahardener, are obtained by using an aromatic diamine instead of hightoxic aniline as a reactant, thereby favoring mass production.

[0045] The hydrocarbon solvents used for preparing the azaoxaheterocyclic compound of the present invention include aliphatichydrocarbon solvents, alicyclic hydrocarbon solvents, aromatichydrocarbon solvents or liquid state olefin compounds. The examples ofan aliphatic hydrocarbon solvent include, but are not limited to,butane, isobutane, tetramethylbutane, pentane, ethylpentane,trimethylpentane, hexane, methylhexane, ethylhexane, dimethylhexane,heptane, methylheptane, octane, nonane, decane, hexadecane, octodecaneand the like. The examples of an alicyclic hydrocarbon solvent include,but are not limited to, cyclopentane, cyclohexane, cyclooctane,cycloheptane, methylcyclopentane, methylcyclohexane, methylcycloheptaneand the like. The examples of an aromatic hydrocarbon solvent include,but are not limited to, benzene, toluene, xylene, ethyl benzene,isopropylbenzene, methylisopropylbenzene, naphthalene and the like. Theexamples of an alicyclic hydrocarbon solvent include, but are notlimited to, ethylene, propene, 1-butene, butadiene, cyclopentene,3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 1,4-hexadiene,1-octene, 1-decene and the like. Among them, aromatic hydrocarbonsolvents are preferred, and toluene and xylene are particularlypreferred.

[0046] The polar solvents used by the conventional method are, forexample, alcohol solvents such as methanol, ethanol, propanol,isopropanol, ethandiol and the like; ether solvents such as1,2-dimethoxy-ethane, tetrahydrofuran, dioxane and the like; ketone suchas acetone, methyl ethyl ketone, methyl isopropyl ketone and the like;and ester solvent such as methyl acetate, ethyl acetate and the like. Incomparison to the above polar solvents, the hydrocarbon solvents used inthe present invention have relatively low polarity. When thesehydrocarbon solvents are used for preparing the compounds having thebenzoxazine cyclic structure, the miscibility between the solvent andthe reactants is poor. The hydrocarbon solvent can dissolve the phenoliccompound and the aromatic diamine compound, but it only can scatter thealdehyde compound so that the agglomeration does not easily occur.Therefore, the stability of the reaction system is enhanced, and thusthe formed compounds having the benzoxazine cyclic structure will notfurther undergo the ring-opening polymerization at very high temperaturecaused by the improper temperature-control.

[0047] Therefore, the present invention provides a method for preparingazaoxa heterocyclic compounds, comprising undergoing the polymerizationof a phenolic compound, an amine compound and an aldehyde compound inthe hydrocarbon solvent. The phenolic compounds, the amine compounds andthe aldehyde compounds used in the present invention are notparticularly limited. In addition to the compounds represented by theabove formulae (II) and (III), a variety of phenolic compounds, aminecompounds and aldehyde compounds for preparing azaoxa heterocycliccompounds having the benzoxazine cyclic structure can be used.

[0048] In addition to the phenolic compounds represented by the aboveformulae (II), phenolic compounds for preparing azaoxa heterocycliccompounds having the benzoxazine cyclic structure include otherbi-functional phenolic compounds such as bisphenol A, bisphenol F,bisphenol AD, bisphenol S, tetramethylbisphenol AD, tetramethylbisphenolS, tetramethylbisphenol A, tetramethylbisphenol F, 4′,4-bisphenol,3′,3-dimethyl-4,4′-bisphenol, 3′,3,5,5′-tetramethyl-4,4′-bisphenol,4,4′-dihydroxy benzophenone, 4,4′-dihydroxy anthraquinone, 1,6-dihydroxynaphthalene and 2,2′-dihydroxy azabenzene; and multi-functional compoundsuch as tris(4-hydroxyphenyl)methane, tris(4-hydroxyphenyl)ethane,tris(4-hydroxyphenyl)propane, tris(4-hydroxyphenyl)butane,tris(3-methyl-4-hydroxyphenyl)methane,tris(3,5-dimethyl-4-hydroxyphenyl)methane,tetrakis(4-hydroxyphenyl)ethane andtetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane.

[0049] In addition to the aromatic diamine compounds represented by theabove formulae (III), amine compounds for preparing azaoxa heterocycliccompounds having the benzoxazine cyclic structure can be the primaryamine compounds including an unsubstituted aromatic amine compound or aaromatic amine compound substituted with halogen, alkyl groups or alkoxygroups such as aniline, 4-chloroaniline, 4-methylaniline,4-isopropylaniline, 4-methoxyaniline, 4-ethoxy-2-methylaniline and thelike; and a substituted or an unsubstituted aliphatic and alicycliccompounds such as methylamine, ethylamine, ethylenediamine,diethylenediamine, aminocyclohexane, 4-methylaminocyclohexane,4-methoxyaminocyclohexane, 4,4′-methylene dicyclohexylamine,2,2′-dimethyl-4,4′-methylene dicyclohexylamine, 1,2-cyclohexanediamine,1,3-diaminomethylcyclohexane, 2,5-diaminomethylnorbornane and the like.

[0050] The method for preparing azaoxa heterocyclic compounds using thehydrocarbon compounds as a solvent renders the system undergoing thereaction under relatively stable conditions, thus effectively solvingthe conventional agglomeration associated with the miscibility problemsdue to using high polar protic solvent to undergo the reaction.Furthermore, among them, the aromatic hydrocarbon solvents arepreferred, and toluene and xylene are particularly preferred. Suchsolvents can be recovered below 130° C. after the completion of thereaction, so that the formed azaoxa heterocyclic compound does notfurther undergo ring-opening reaction at high temperature as recoveringthe solvent.

[0051] The compounds of the present invention prepared by undergoing thereaction of the substituted phenolic compounds and aromatic diaminecompounds are examined by IR spectrum. It found that the absorption ofthe compounds at 3000 to 3500 cm⁻¹ is very low, thus proving no largeamount of hydroxy groups existing in the compounds. The absorption at1480 to 1500 cm⁻¹ shows 2-substituted structure of a benzene ring, andthe absorption at 940 to 950 cm⁻¹ and 1220 to 1230 cm⁻¹ shows that theC—O—C cyclic structure of acetal is formed. Therefore, the formed azaoxaheterocyclic compound having the benzoxazine cyclic structure isdetermined.

[0052] The present azaoxa heterocyclic compound having the benzoxazinecyclic structure can be used as hardener for epoxy resins, polyesterresins or resins having active hydrogen atoms due to the ring-openingpolymerization of the benzoxazine cyclic structure. The characteristicsof such an azaoxa heterocyclic compound are low viscosity, high thermalstability and low volatility during curing. Such compound is applied formanufacturing CCL, copper foil adhesives, semiconductor packagingmaterials, phenolic resin forming materials and the like.

[0053] The following examples, while not to be construed as limiting innature, are illustrative of the invention.

EXAMPLES Example 1

[0054] 151.4 g of dianilinomethane, 229.5 g of p-t-butylphenol, 98.7 gof 92% of paraformaldehyde and 200 g of toluene were successivelycharged into a 1L of four-neck reaction vessel equipped with a stirrer,thermometer, pressure reducing system, and condensing-heating mantle.After heated up to 80° C., the electric source for heating was shut. Thereaction is conducted for 3 hours while maintaining the temperature inthe range of 85 and 90° C. Subsequently, in order to recover toluene,the internal pressure was reduced and the temperature was raised. Afterreaching the temperature of 150° C. and the vacuum pressure of more than650 mm Hg and after recovering all of toluene, the solid azaoxaheterocyclic compound having the benzoxazine cyclic structure of thepresent invention was discharged. Alternatively, the solvent can bedirectly charged into the reaction vessel, and the azaoxa heterocycliccompound was present in a solvent form. The compound was analyzed byInfrared spectroscopy (IR) and gel permeation chromatography (GPC), andthe results were shown in FIG. 1 and FIG. 2.

Example 2

[0055] The procedure of Example 1 was repeated with the exception thatxylene was used as a solvent. The compound was analyzed by IR and GPC,and the results were shown in FIG. 3 and FIG. 4.

Example 3

[0056] The procedure of Example 1 was repeated with the exception thatmethyl ethyl ketone was used as a solvent. The compound was analyzed byIR and GPC, and the results were shown in FIG. 5 and FIG. 6.

Example 4

[0057] 240 g of dianilinomethane, 228 g of phenol, 156.8 g of 92% ofparaformaldehyde and 300 g of toluene were successively charged into a1L of four-neck reaction vessel equipped with a stirrer, thermometer,pressure reducing system, and condensing-heating mantle. After heated upto 50° C., the electric source for heating was shut. The reaction isconducted for 2.5 hours while maintaining the temperature in the rangeof 85 and 90° C. Subsequently, in order to recover toluene, the internalpressure was reduced and the temperature was raised. After reaching thetemperature of 130° C. and the vacuum pressure of more than 650 mm Hgand after recovering all of toluene, the solid azaoxa heterocycliccompound having the benzoxazine cyclic structure of the presentinvention was discharged. Alternatively, the solvent can be directlycharged into the reaction vessel, and the azaoxa heterocyclic compoundwas present in a solvent form. The compound was analyzed by IR and GPC,and the results were shown in FIG. 7 and FIG. 8.

Example 5

[0058] The procedure of Example 4 was repeated with the exception thatxylene was used as a solvent. The compound was analyzed by IR and GPC,and the results were shown in FIG. 9 and FIG. 10.

Comparative Example 1

[0059] The procedure of Example 4 was repeated with the exception thatmethyl ethyl ketone was used as a solvent. The compound was analyzed byIR and GPC, and the results were shown in FIG. 11 and FIG. 12.

[0060] The system using hydrocarbon compound as a solvent existedrelatively low gelation or agglomeration and was relatively stablecomparing with the system using methyl ethyl ketone as a solvent.

Comparative Example 2

[0061] According to the ratios shown in Table 1, epoxy resins, ahardener, a hardening promoter and a solvent were formulated an epoxyresin varnish in a vessel equipped with a stirrer and a condenser:

[0062] BEB530A80 represents a bisphenol A type epoxy resin with lowbromine content manufactured by Chang Chun Plastics Co., Ltd., and theepoxy equivalent weight thereof is in the range of 420 to 450 g/eq. Thehydrolytic chlorine content is below 500 ppm, the bromine content is inthe range of 18 to 20 weight % , and the solid content is the range of79 to 81 weight % . The solvent is acetone. The viscosity is in therange of 1200 to 1800 cps/25° C.

[0063] BEB580A75 represents a high heat resistant epoxy resin with lowbromine content manufactured by Chang Chun Plastics Co., Ltd., and theepoxy equivalent weight thereof is in the range of 300 to 340 g/eq. Thehydrolytic chlorine content is below 500 ppm, the bromine content is inthe range of 23 to 26 weight % , and the solid content is the range of74 to 76 weight % . The solvent is acetone.

[0064] TNE190A70 represents a multi-functional epoxy resin manufacturedby Chang Chun Plastics Co., Ltd., and the epoxy equivalent weightthereof is in the range of 200 to 220 g/eq. The hydrolytic chlorinecontent is below 1000 ppm, and the solid content is the range of 69 to71 weight % . The solvent is acetone. The viscosity is in the range of50 to 200 cps/25° C.

[0065] PF3800M60 represents an azaoxa heterocyclic compound preparedfrom phenol, dianilinomethane and paraformaldehyde, which wasmanufactured by Chang Chun Plastics Co., Ltd.

[0066] PF3900M60 represents an azaoxa heterocyclic compound preparedfrom p-t-butylphenol, dianilinomethane and paraformaldehyde, which wasmanufactured by Chang Chun Plastics Co., Ltd. TABLE 1 ComparativeComparative Comparative Comparative Example 2-1 Example 2-2 Example 2-3Example 2-4 BEB530A80 — 200 — 200 (g) BEB580A75 200 — 200 — (g)TNE190A70 3.0 4.6 3.0 4.6 (g) PF800M60 — 191 155 (g) PF3900M60 237 91 —— (g) 10% 2MI 2.33 3.3 22.5 3 Propylene-gly- 0 21 8 23 col momometh- ylether

[0067] A glass-fiber fabric was impregnated in the epoxy resin varnishprepared above, then dried at 160° C. for 8 to 10 minutes so thatprepregs were formed. Eight pieces of the above prepregs were piled up,and a sheet of 35 μm copper foil was placed on the top and bottom sidesof the eight prepregs, then laminated at 185° C. under a pressure of 25kg/cm² to form a laminated entities of the prepregs and the glass fiberfabric. The glass transition temperature was measured by DSC(Differential Scan Calorimeter, TA 2910) (the temperature is in therange of 50 to 250° C., a rate of temperature rise is 20° C./min). Theinflammability was measured by a flame test according to the method ofUL746. Th resulting prepreg specimen is cut into five pieces of 12.5mm×1.3 mm. A flame is applied to each piece twice. The sum of thecombustion periods for ten tests must not exceed 50 seconds, and thecombustion period for each test must not exceed 10 seconds to pass theburning test. TABLE 2 The inflammability and the glass-transitiontemperatures of films after baking at 150° C. for 120 minutes.Comparative Comparative Comparative Comparative Example 2-1 Example 2-2Example 2-3 Example 2-4 The sum of 15 18 17 22 the combus- tion periods(sec.) Tg (° C.) 189.5° C. 145.3°πC. 191.6° C. 144.6° C.

[0068] Results of physical property tests on each laminate are shown inTable 3. TABLE 3 Comparative Comparative Comparative Comparative TestItem Example 2-1 Example 2-2 Example 2-3 Example 2-4 Tg (° C.) 192.5° C.145.3° C. 191.6° C. 144.6° C. Burning Test pass pass pass passSolder >300 sec. >300 sec. >300 sec. >300 sec. Resistance (288° C.)Peeling 1.7 1.9 1.7 1.9 Strength (kgf/cm) Surface 3.9 * 10¹⁴ 2.6 * 10¹⁴5.5 * 10¹⁴ 1.78 * 10¹⁴ Resistance Volume 6.2 * 10¹⁵ 7.2 * 10¹⁵ 3.1 *10¹⁵ 6.9 * 10¹⁵ Resistance Dielectric 4.4 4.5 4.5 4.6 ConstantDissipation 0.009-0.011 0.013-0.015 0.009-0.012 0.013-0.016 Coefficientwater 0.262% 0.214% 0.373% 0.326% absorbency

[0069] As shown in Table 3, in the same resin system the waterabsorbency of the laminate manufactured by using the azaoxa heterocycliccompound (PF3900) prepared from alkylphenol as a hardener was apparentlydecreased 30% comparing with that of the laminate manufactured by usingthe azaoxa heterocyclic compound (PF3800) prepared from phenol as ahardener.

[0070] Although the present invention was described above with referenceto the examples, the present invention is not limited thereto, andvarious modification and additions may be made without departing fromthe spirit of the invention which is defined by the following claims.

What is claimed is:
 1. An azaoxa heterocyclic compound represented bythe following formula (I):

wherein, R₁ is one selected from the group consisting of an alkyl group,an alkenyl group, an alkoxyl group, a hydroxy group, halogen and anamino group; R₂ is one selected from the group consisting of a bond, analkylene group, O, S and SO₂; R₃ is H or C₁-C₆ alkyl group; m is aninteger of 0 to 4; and n is an integer of 1 to
 4. 2. The azaoxaheterocyclic compound according to claim 1, wherein R₁ is an alkylgroup.
 3. The azaoxa heterocyclic compound according to claim 1, whereinthe alkyl group is t-butyl.
 4. The azaoxa heterocyclic compoundaccording to claim 1, wherein R₂ is an alkylene group.
 5. The azaoxaheterocyclic compound according to claim 1, wherein the alkylene groupis a methylene group.
 6. The azaoxa heterocyclic compound according toclaim 1, wherein R₃ is hydrogen.
 7. The azaoxa heterocyclic compoundaccording to claim 1, wherein m is
 1. 8. The azaoxa heterocycliccompound according to claim 1, wherein n is
 1. 9. The azaoxaheterocyclic compound according to claim 1, wherein the azaoxaheterocyclic compound is prepared by the reaction of a phenoliccompound, an aromatic diamine compound and an aldehyde compound.
 10. Theazaoxa heterocyclic compound according to claim 9, wherein the phenoliccompound is represented by the following formula (II):

wherein R₁ and n are as defined above.
 11. The azaoxa heterocycliccompound according to claim 10, wherein the phenolic compound is analkylphenol compound.
 12. The azaoxa heterocyclic compound according toclaim 11, wherein the alkylphenol compound is p-t-butylphenol.
 13. Theazaoxa heterocyclic compound according to claim 9, wherein the aromaticdiamine compound is represented by the following formula (III):

wherein R₂, R₃ and m are as defined above.
 14. The azaoxa heterocycliccompound according to claim 14, wherein the aromatic diamine compound isdianilinomethane.
 15. The azaoxa heterocyclic compound according toclaim 1, wherein the azaoxa heterocyclic compound is used as a hardener.16. The azaoxa heterocyclic compound according to claim 1, wherein anepoxy resin composition is formed by the azaoxa heterocyclic compoundand an epoxy resin.
 17. The azaoxa heterocyclic compound according toclaim 16, wherein the epoxy resin composition is useful in theapplication of the laminate, adhesive, semiconductor packaging materialand material made of phenolic resin.
 18. A method for preparing theazaoxa heterocyclic compound, comprising undergoing the polymerizationreaction of phenolic compound, amine compound and aldehyde compoundusing a hydrocarbon solvent to form the compound having the benzoxazinecyclic structure, wherein at least one of hydrogen atoms onortho-positions to the hydroxy group in the phenolic compound isunsubstituted and the amine compound is a primary amine compound. 19.The method according to claim 18, wherein the phenolic compound isrepresented by the following formula (II):

wherein R₁ and n are as defined above.
 20. The method according to claim19, wherein the phenolic compound is an alkylphenol.
 21. The methodaccording to claim 20, wherein the alkylphenol is p-t-butylphenol. 22.The method according to claim 20, wherein the amine compound is anaromatic diamine compound.
 23. The method according to claim 22, whereinthe aromatic diamine compound is represented by the following formula(III):

wherein R₂, R₃ and m are as defined above.
 24. The method according toclaim 18, wherein the aldehyde is formaldehyde or paraformaldehyde. 25.The method according to claim 18, wherein the hydrocarbon solvent is oneselected from aliphatic hydrocarbon solvents, alicyclic hydrocarbonsolvents, aromatic hydrocarbon solvents and liquid state olefincompounds.
 26. The method according to claim 25, wherein the hydrocarbonsolvent is an aromatic hydrocarbon solvent.
 27. The method according toclaim 26, wherein the aromatic hydrocarbon solvent is toluene.
 28. Themethod according to claim 26, wherein the aromatic hydrocarbon solventis xylene.